Process of manufacturing base of diamond abrasive stone

ABSTRACT

A process for manufacturing the base of a diamond abrasive stone wherein a steel plate having a plurality of oval holes is bonded to a plastic base in a casting process so that plastic material is forced through the holes. Layers of nickel diamond material is applied to the surface of the steel plate.

This application is a continuation of non-provisional application Ser. No. 10/686,032 filed Oct. 16, 2003.

BACKGROUND OF THE INVENTION

This invention relates to the fabrication of plastic members and more particularly to a process to manufacture the base for a diamond abrasive stone.

SUMMARY OF THE PRIOR ART

Abrasive stones are often affixed to a plate that is attached to a base such as formed from plastic. Many molding processes are employed in the prior art to fabricate the base supporting abrasives. It is known to apply abrasive stones through a metal plate affixed to the base, such as formed from plastic. Prior techniques, however, have been defective in providing optimum bonding between the plate and base, and do not provide a suitable low shrink rate.

SUMMARY OF THE INVENTION

It is therefore, an objective of the invention to provide a process for fabricating the base of a diamond bench abrasive stone for sharpening knives and the like The process provides a superior bond between a steel plate and the base. After formation and bonding, the block is then plated with diamond abrasive and nickel.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a top plan view of the abrasive diamond stone assembly made in accordance with the process of the invention;

FIG. 2 is a side elevational view of the stone assembly of FIG. 1;

FIG. 3 is a bottom plan view of stone assembly of FIG. 1; and

FIG. 4 is an end elevational view of the stone assembly of FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring now to FIGS. 1 and 2, there is illustrated the diamond stone assembly, generally designated by reference numeral 2, having base assembly 2 made in accordance with the process of the invention. The base assembly 2 includes a lower plastic base on which a plate 6 is bonded in accordance with the invention. The plastic base 4 includes an upper wall 8 (FIG. 3) and four opposed upright longitudinal walls 10 and opposed upright lateral walls 12 to form cavity 14. A longitudinal rib 16 extends within the cavity and connects with a plurality of lateral rib segments 18.

The upper steel plate 6 is manufactured with oval holes 22 with conventional progressive punching equipment. The holes 22 are punched through the steel plate in lateral rows 22 in the pattern shown in FIG. 1 across a substantial portion of the steel plate except for the unpunched area 24. After the steel plate 6 is punched, it is de-burred and nickel-plated on its bottom to prevent any rust or oxidation developing between the plastic base 4 and the steel plate 6. The plate 6 is applied to the plastic base prior to the molding procedure. The plastic base is fabricated by molding in conventional molding machines and constructed with a 40 mm curvature, which in fact results in a flatter, straighter part coming out of the molding. Once the base is molded, then the flash (excess plastic material) is removed from the top surface and from all four edges.

The molding process causes the plastic base material to be forced through the holes 22 of the top steel plate 6, assuring that 100% of the surface area of the steel plate 6 is bonded to the plastic base 4. After excess plastic is removed, the surface of the steel plate 6 is ground on a horizontal surface grinder using an aluminum oxide abrasive grinding wheel to remove any blemishes and to guarantee 100% flattening.

After grinding, the base assembly is thoroughly cleaned and flash nickel plated, rinsed, and cleaned and then nickel diamond plated three times on the exposed metal surface of the plate 6 as shown in FIG. 1, resulting in three layers of diamond particles and a final layer of nickel plating to fill in any voids and to strengthen the bond of the diamonds. The plastic base 4 is formed from resin formed from glass fiber, plastic resin and a filler. Other ingredients in the form of pigments, accelerants, and low shrinkage ingredients are added. During the molding process, the steel sheet are molded together for more than five minutes with the mold being heated to 190°. 

1. A process for manufacturing an abrasive stone comprising the steps of punching a plurality of holes through a flat steel plate, de-burring said steel plate and nickel plating the bottom of said plate, applying said steel plate to a plastic material, casting the plastic material to form a base and forcing the plastic material through said plurality of holes, grinding the surface of said steel plate, applying flash nickel plating to the surface of said plate, and plating a nickel diamond material three times on the surface on the surface of said plate.
 2. The process according to claim 1 wherein said holes are oval and extend laterally across the plate in rows.
 3. The process according to claim 2 wherein a portion of the steel plate is free of holes.
 4. A process of manufacturing a base for an abrasive stone comprising the steps of punching a plurality of holes through a flat steel plate, applying a steel plate to a plastic base, molding the plastic base together with steel plate, forcing the plastic material of the base through said plurality of holes during said molding and form the base for the abrasive stone.
 5. The process according to claim 4 wherein a portion of said steel plate is not punched with a plurality of holes.
 6. The process according to claim 4 wherein said holes are oval and extend laterally across said plate in rows other than said portion.
 7. The process according to claim 4 further comprising the step of grinding the surface of the metal plate to remove excess plastic 